alpha-Sulfonyl Carbanion-Transition-Metal Bonds. Alkali-Metal alpha-Sulfonyl Carbanions and Their Reactivity with Metal Complexes

Deprotonation of p-MeC(6)H(4)SO(2)Me (1) with KH in THF in the presence of 18-crown-6 led to the isolation of the ion contact pair [p-MeC(6)H(4)S(CH2)O-2- - -K(18-crown-6)] (2). The alpha-sulfonyl carbanion has been involved in the derivatization of both early- and late-transition-metal complexes. When the deprotonation of 1 in situ was followed by a reaction with Cp(2)TiCl(2) (Cp eta(5)-C5H5), we obtained a Ti-C-bonded alpha-sulfonyl complex, [Cp(2)Ti(Cl)(CH2-SO (2)C(6)H(4)Me-p)] (4), while the reaction of 2 with Cp(2)ZrCl(2) led to a 1:1 mixture of Zr-C- and Zr-O-bonded alpha-sulfonyl complexes, [Cp(2)Zr(Cl)(CH(2)SO(2)C(6)H(4)Me-p)] (5a) and [Cp(2)Zr(Cl)-(O2S(CH2)C(6)H(4)Me-p)] (5b). The reaction of the alpha-sulfonyl carbanion derived from 1 with [cis-Pd(PPh(3))(2)Cl-2] gave a Pd-C-bonded alpha-sulfonyl complex occurring with the isomerization of the metal center, [trans-(PPh(3))(2)(Cl)Pd-CH2SO2(p-MeC(6)H(4))] (7). Crystallographic details: 2 is monoclinic, space group P2(1)/c, with a = 8.635(2) Angstrom, b = 14.879(3) Angstrom, c = 19.589(3) Angstrom, alpha = gamma = 90 degrees, beta = 96.30(2)degrees, Z = 4, and R = 0.057; 4 is monoclinic, space group C2/c, with a = 22.318(3) Angstrom, b = 9.727(2) Angstrom, c = 16.267(3) Angstrom, alpha = gamma = 90 degrees, beta 100.08(2)degrees, Z = 8, and R = 0.047.